一、概述为了满足航运事业发展的需要,广东文冲船厂先后兴建二座万吨级干船坞。二船坞均建于广州市东郊文冲,傍依珠江。该地区的地基,为淤泥质粘土、亚粘土、淤泥等土层,土质十分软弱。一号船坞,于1959年进行水下开挖,后停工,至1963年复工。为了确保边坡的稳定,采用二级轻型真空井点降低地下水位,而后抽干坞坑积水。这是在粘土地基上采用井点降水的初次尝试。由于在井点运转过程中,发生较大的沉陷及裂缝,故采取削坡措施以策安全。边坡达1:8～1:5。曾结合此项工程进行研究,在室内试验方面,初次考虑了卸荷作用对抗剪强度的影响;在分析方法方面,论证了井点的作用,并将有效 I. Overview In order to meet the needs of the development of the shipping industry, Guangdong Wenchong Shipyard successively built two 10,000-ton dry docks. The two docks are built in Wenchong, the eastern suburbs of Guangzhou, and they rely on the Pearl River. The foundation of the area is muddy clay, sub-clay, silt and other soil layers, and the soil is very weak. The No. 1 dock was under sea excavation in 1959, and then stopped working until 1963. In order to ensure the stability of the slope, a secondary light vacuum well is used to lower the groundwater level, and then the water in the dock is drained. This is the first attempt to use well-point precipitation on a clay foundation. Due to the occurrence of large subsidence and cracks during the operation at the well site, slope cutting measures are adopted to ensure safety. The slope reaches 1:8 to 1:5. This project has been studied in conjunction with this project. In indoor testing, the impact of unloading on shear strength was considered for the first time; in terms of analytical methods, the role of well points was demonstrated and will be effective.